Charlotte Sena, 9, vanishes during bike ride in Moreau Lake State Park

A 9-year-old girl went missing during a bike ride while camping at New York’s Moreau Lake State Park with her family — and police scoured the area for 18 hours before issuing an Amber Alert.

Charlotte Sena, of Greenfield, NY, was enjoying a family outing on Saturday evening when she decided to make one last loop around their picnicking field by herself, Gov. Kathy Hochul said in a press conference Sunday.

Sena, the niece of a local firefighter, set off on Loop A on her bike at around 6:15 p.m., to prove she was “one of the big kids,” but she never came back.

Hochul said the girl’s family was distraught over the sudden disappearance.

“The family was here to make memories, the kind that would last a lifetime. Instead, it turned into every parent’s nightmare,” Hochul said.

When Sena failed to return within 15 minutes, her family and fellow campers went out to look for her, with police called to the scene at around 6:47 p.m.

The 9-year-old’s bike was found on Loop A, with a 100-person search party composed of state troopers, special ops, forest rangers, park police and civilian volunteers converging at the scene.

Since Sena’s disappearance, NY State Police Lt. Col. Richard Mazzone said his team had conducted an extensive 18-hour search of the park, with police believing the child is no longer there.

As of 9:45 a.m. Sunday, police issued an Amber Alert, fearing that Sena might have been abducted when she was by herself.

Along with issuing the alert, Mazzone said officials will continue to search the area for Sena, with an aquatic search team also deployed to check the nearby waterways.

“We continue to dedicate all the resources that we can to find Charlotte and bring her home safe,” Mazzone said.  

Sena was described as a white child with blond hair, standing at 5-foot 1 and weighing 90 pounds. She was last seen wearing an orange tie-dye Pokemon shirt, dark blue pants, black Crocs and a gray bike helmet.

Officials described the fourth grader as an intelligent and adventurous girl who was recently elected for her school’s student council.